1. Field of the Invention
This invention relates to arc extinguishing means for use with loadbreak contacts of the type wherein a male contact probe is inserted in or withdrawn from a female probe receiving contact to make or break respectively a load current. Insulating members formed of arc extinguishing materials are positioned to surround, and in some cases block, the arc which may be established between the loadbreak contacts.
2. Description of the Prior Art
In the past various arrangements have been provided to surround, and in some cases block with insulating arc extinguishing materials, an arc established between loadbreak contacts. Some such arrangements have been disclosed for use with loadbreak fuseholders. For instance, in U.S. Pat. No. 3,628,092, issued Dec. 14, 1971, there is revealed an arrangement wherein a probe contact is provided with a cylindrical insulating tip, and a tubular insulating member surrounds, and is carried with a movable tubular contact. When the probe contact is withdrawn from the tubular contact the insulating tip follows the probe contact through a portion of the tubular insulating member which has an opening providing a close sliding fit with the insulating tip to confine, squeeze and extinguish the arc therebetween. However, due to the confining and squeezing of the arc, the hot gases making up the arc tend to "squirt" out of the confined volume at high velocities. The laminar flow of the hot gases in the confined volume contributes to the high velocities. Thus, problems are presented in further confining and cooling the gases after they exit the confined volume. U.S. Pat. No. 3,732,517, issued May 8, 1973, reveals an arc snuffing device wherein a spring loaded movable member or members close a deionizing chamber around one of the loadbreak contacts following separation of the loadbreak contacts. Thus, the arc is interrupted in and a major portion of the arc is confined within the deionizing chamber. However, the addition of the movable members, and the springs applying forces thereto, complicates the structure and increases the possibilities of the arc not being extinguished through failure of the movable members to operate to choke off the arc.
Therefore, it is accordingly an object of this invention to provide an improved arc quenching arrangement for use with loadbreak contacts of the type wherein a contact probe is inserted in or withdrawn from a probe receiving contact to make or break a load current carrying circuit. It is a further object of this invention to provide improved arc quenching with a minimum number of components in a device which is readily assembled and is reliable in operation.